Upset recovery training using a sustained-G multi-axis platform or a centrifuge

ABSTRACT

A process for providing upset recovery training (URT) includes using a sustained-G multi-axis platform (e.g., a centrifuge-based simulator). Various embodiments of the present invention address an important aspect of URT that is not present in the prior art, namely the placing of physiological stresses on the trainees during URT, such as sustained motions including, but not limited to, sustained, elevated G-forces and continuous rotational cues. Elevated, sustained, G-forces and continuous rotational cues can create many physiological challenges to aircrew. These challenges can include motion discomfort, disorientation, and visual disturbances. Embodiments of the present invention provide URT that includes physiological stresses on the pilot. If a pilot learns the correct procedures for recovery from an upset, as in the prior art URT programs, but cannot execute the procedures in the real world because he or she has not been prepared for the physiological environment to be faced, then safety is compromised.

CROSS-REFERENCE TO RELATED APPLICATIONS

This non-provisional application claims the benefit of US ProvisionalApplication No. 61/273,607, filed 6 Aug. 2009, and entitled “A ProcessFor Upset Recovery Training Using A Sustained-G Multi-Axis Platform Or ACentrifuge”, the entirety of which is hereby incorporated by reference.

COPYRIGHT AUTHORIZATION LANGUAGE UNDER 37 CFR §1.71(e)

A portion of the disclosure of this patent document contains materialwhich is subject to copyright protection. The copyright owner has noobjection to the facsimile reproduction by anyone of the patent documentor the patent disclosure, as it appears in the Patent and TrademarkOffice patent file or records, but otherwise reserves all copyrightrights whatsoever.

FIELD OF THE INVENTION

The present invention relates to an upset recovery training process thatemploys a sustained G-force multi-axis platform to train pilots in howto recover and gain control of their aircraft in an upset situation.

BACKGROUND

Accidents resulting from a loss of airplane control, sometimes referredto as airplane “upsets”, are a major cause of fatalities in thecommercial aviation industry.

The following unintentional flight conditions generally describe anairplane upset: pitch attitude greater than 25 degrees nose up; pitchattitude greater than 10 degrees nose down; bank angle greater than 45degrees; and within the foregoing parameters, but flying at airspeedsinappropriate for the conditions.

The causes of airplane upset incidents are varied, however, they can bebroken down into four broad categories, namely: environmentally induced;system-anomalies induced; pilot induced; and a various combinations ofthe foregoing categories.

Environmentally induced airplane upsets include the following:turbulence; clear air turbulence, mountain wave turbulence, wind shear,thunderstorms, microbursts, wake turbulence, and airplane icing.

Turbulence is characterized by a large variation in an air current overa short distance. It is caused by, among other things, jet streams,convective currents, obstructions to wind flow, and wind shear.Knowledge of the various types of turbulence assists in avoiding it,and, consequently, reduces the potential for an airplane upset.

Clear air turbulence (CAT) is defined as high-level turbulence, as it isnormally above 15,000 MSL (mean sea level). It is not associated withcumuliform cloudiness. CAT is almost always present near jet streams.Jet streams are dynamic, and turbulence associated with them isdifficult to predict. This area of turbulence can be 100 to 300 mileslong, 50 to 100 miles wide, and 2000 to 5000 feet thick.

Mountains are the greatest obstructions to wind flow. This type ofturbulence is classified as “mechanical.” Lenticular clouds overmountains are a sure sign of mountain wave turbulence, but unfortunatelythe air may be too dry for the presence of the telltale clouds,increasing the likelihood of upsets.

Wind shear wind variations at low altitude are recognized as a serioushazard to airplanes during takeoff and approach. These variations can becaused by many differing meteorological conditions including, but notlimited to, topographical, temperature inversions, sea breezes, frontalsystems, strong surface winds, thunderstorms, and microbursts.Thunderstorms and microbursts are the two most violent forms of windchange.

The two basic types of thunderstorms are air mass and frontal. Air massthunderstorms are randomly distributed in unstable air. Heated air risesto form cumulus clouds. The clouds develop in three stages: cumulusstage, mature stage, and dissipating stage. The gust front produced bythe downflow and outrush of rain-cooled air can produce very turbulentair conditions.

Frontal thunderstorms are associated with weather system line fronts,converging wind, and troughs aloft. Frontal thunderstorms form in squalllines, last several hours, generate heavy rain and possibly hail, andproduce strong gusty winds and possibly tornadoes. The downdraft of atypical frontal thunderstorm is large, about 1 to 5 miles in diameter.Resultant outflows may produce large changes in wind speed.

Microbursts can occur anywhere that convective weather conditions occur.Five percent of all thunderstorms produce microbursts. Downdrafts aretypically only a few hundred to 3,000 feet across. The outflows are notalways symmetrical. A significant airspeed increase may not occur uponentering outflows, or it may be much less than the subsequent airspeedloss experienced when exiting. Some microbursts are so severe that anaircraft cannot escape them.

Wake turbulence is a leading cause of airplane upsets that areenvironmentally induced. A pair of counter-rotating vortices is shedfrom an airplane wing, thus causing turbulence in the airplane's wake.The effect of turbulence on the aircraft is a function of airplaneweight, wingspan, and speed. Vortices descend at an initial rate of 300to 500 feet/minute for about 30 seconds. Pilots have likened awake-turbulence encounter to be like hitting a wall. With little to nocontrol input from the pilot, the airplane would be expelled from thewake and an airplane upset could result.

With regard to airplane icing, large degradation of airplane performancecan result from the surface roughness of an extremely small amount ofice contamination. The handling characteristics and lift capability canbe adversely affected. Therefore, the axiom of “keep it clean” forcritical airplane surfaces continues to be a universal requirement.

System-anomalies induced airplane upsets can arise from the failure ofitems such as airplane systems (i.e., engines, electric, hydraulic, andflight controls), flight instruments and auto-flight systems as well asother anomalies. These types of failures can range from unrecoverable tosurvivable if the flight crew makes correct responses.

Airplane system failures involve the loss or degradation of one or moreaircraft systems. Primary airplane systems include engines, electric,hydraulic, and flight controls. Emergency procedures are published formany systems failures. Successful resolution of a system failureinvolves the pilot recognizing the failure and maintaining aircraftcontrol while executing the proper emergency procedure.

With regard to instrument failures, virtually all airplane operationsmanuals provide flight instrument system information that the pilot cananalyze to select the correct procedural alternatives. Several accidentshave pointed out that pilots are not always prepared to correctlyanalyze the alternatives in case of failure. The result can becatastrophic.

Auto-flight systems include autopilot, auto-throttles, and all relatedsystems that perform automatic control of the aircraft, flightmanagement, and guidance. The pilot community has tended to develop agreat deal of confidence in these systems, which has led to complacencyin some cases. Although quite reliable, failures do occur. Thesefailures have led to airplane upsets and accidents.

Flight controls include primary flight controls (ailerons/spoilers,rudder, and elevator/stabilizer) and secondary flight controls(including trim surfaces, flaps, and speedbrakes). Flight control damageor failure can occur due to a variety of reasons including mechanicalfailure, bird strike, or overstress. These failures and other anomaliessuch as flap asymmetry, runaway trim and aileron/spoiler problems areaddressed in airplane operations manuals. Airplane certificationrequirements ensure that pilots have sufficient information and aretrained to handle these critical failures. However, it is the unexpectedthat can cause problems, and an accident.

With regard to pilot-induced airplane upsets, it has been known for manyyears that sensory inputs can be misleading to pilots, especially whenpilots cannot see the horizon. To solve this problem, airplanes areequipped with flight instruments to provide the necessary informationfor controlling the airplane. However, a review of airplane upsetsreveals that pilot inattention to, or neglect of, the airplane'sperformance can lead to extreme deviations from the normal flightenvelope. Distractions can be very subtle, such as warning or cautionlights illuminating during critical phases of flight, conflictingtraffic, or radio calls during critical phases of flight. Many airplaneupsets occur while the pilot is engaged in some task that takesattention away from the flight instruments.

Spatial disorientation has been a significant factor in many airplaneupset accidents. The definition of spatial disorientation is theinability to correctly orient oneself with respect to the Earth'ssurface due to misinterpretation of the aircraft position and/or motion.We are all susceptible to sensory illusions. Pilots who perceive aconflict between bodily senses and the flight instruments and are unableto resolve the conflict are spatially disoriented. Allowed to continue,a spatial disorientation episode will likely lead to an airplane upset.Attention to flight instruments and a good cross-check are the keys toremaining spatially orientated.

The advancement of technology in today's modern airplanes has brought usflight directors, autopilots, auto-throttles, flight management systems,and ground collision avoidance systems. When used properly, thistechnology contributes to flight safety and reduces crew workload.Complacent and improper use of these systems is a concern. The systemscan and do fail, leading to airplane upsets and accidents.

Data from the U.S. National Transportation Safety Board show thatbetween 1993 and 2002, there were 2,131 fatalities in loss of controlaccidents and that some of these fatalities were attributable toairplane upsets. See Docket No. SA-531 Exhibit No. 14-M NationalTransportation Safety Board Washington, D.C. Flight Safety Digest, July.

Another airline industry source reports that there were twenty-twoin-flight, loss-25 of-control accidents between 1999 and 2008. (SeeStatistical Summary of Commercial Jet Airplane Accidents, WorldwideOperations, 1959-2008) These accidents resulted in more than 1,991fatalities.

These accident and fatality statistics suggest that pilots need trainingso that they are better prepared to respond to airplane upsetsituations.

Many commercially trained pilots do not receive training in theprocedures and techniques necessary to recover from an upset. SeeAirplane Upset Recovery Training Aid Revision 2, available online atflightsafety.org. Military pilots, on the other hand, receive upsetrecovery training, but the ratio of military trained pilots tocommercially trained pilots in commercial aviation continues to shifttoward more commercially trained pilots.

The goal of prior art upset recovery training was, since completeavoidance of upsets was not possible, that pilots should be trained tosafely recover an airplane that has been upset.

The goal of prior art upset recovery training programs was, in aclassroom situation, to increase the pilot's ability to recognize andavoid upset situations and to improve the pilot's ability to recovercontrol, if avoidance is not successful.

Most prior art upset recovery training programs are, in a classroomsetting, presented in three parts: (1) the causes of airplane upsets;(2) a brief review of airplane fundamentals; and (3) airplane upsetrecovery techniques.

Airplane manufacturers, airlines, pilot associations, flight trainingorganizations, and government and regulatory agencies have developedthese prior art training resources.

The goal of the prior art training aid has been to increase the abilityof pilots to recognize and avoid situations that can lead to airplaneupsets and to improve their ability to recover control of an airplanethat has exceeded the normal flight regime.

The use of simulators in prior art upset recovery training (“URT”)programs has not been well accepted because a traditional simulatorcannot replicate the sustained motions and accelerations experienced inan actual upset situation. Many believe that use of a simulator createsa potential for negative learning, in that it may, because oflimitations in the simulator being used, reinforce recovery techniquesthat may not work, and may in fact fail catastrophically, in real worldconditions.

In prior art URT programs, ground-based motion simulation of aircrafthas been considered using “six-post” or “hexapod” devices. (See FIG. 1.)In prior art URT programs, ground-based motion simulation of aircrafthas also been considered using a Level D simulator. Level D is asimulator classification by the U.S. Federal Aviation Administration.(See FIG. 2.) Level D flight simulator devices have the followingcharacteristics and components: (1) systems representations, switches,and controls which are required by the type design of the aircraft andby the user's approved training program; (2) systems which respondappropriately and accurately to the switches and controls of theaircraft being simulated; (3) full-scale replica of the cockpit of theaircraft being simulated; (4) correct simulation of the aerodynamic(including ground effect) and ground dynamic characteristics of theaircraft being simulated in the normal flight environment; (5) correctsimulation of selected environmentally-affected aerodynamic and grounddynamic characteristics of the aircraft being simulated considering thefull range of its flight envelope in all approved configurations; (6)correct and realistic simulation of the effects of environmentalconditions which the aircraft might encounter; (7) control forces,dynamics, and travel which correspond to the aircraft; (8) instructorcontrols and seat; (9) a daylight, dusk, and night visual system withthe minimum of a 75° horizontal by 30° vertical field of view for eachpilot station; and (10) a motion system with at least 6 degrees offreedom. These devices are able to provide transient motion cues withlittle addition to the response time that a pilot senses. These devicesare, however, not able to provide sustained acceleration or sustainedmotion cues. This means that flight fidelity is diminished in manymaneuvers such as a basic coordinated turn and particularly duringflight conditions that are outside the normal flight envelope. Thismissing fidelity does not allow training pilots to cope with vestibularand tactile illusions that routinely occur in flight.

What is needed is a method of upset recovery training that replicatesthe sustained motions and accelerations experienced in an actual upsetcondition, thereby allowing pilots to train to cope with the vestibularand tactile stresses that occur in both flight and in an upsetcondition.

SUMMARY OF THE INVENTION

Briefly, a process for providing upset recovery training includes usinga sustained-G multi-axis platform (e.g., a centrifuge-based simulator).

Various embodiments of the present invention address an important aspectof URT that is not present in the prior art, namely the placing ofphysiological stresses on the trainees during URT, such as sustainedmotions including, but not limited to, elevated G-forces and prolongedrotational cues. Elevated G-forces and prolonged rotational cues cancreate many physiological challenges in the aircrew. These challengescan include motion discomfort, disorientation, and visual disturbances.

Various embodiments of the present invention provide URT that includesphysiological stresses on the crew. If a pilot learns the correctprocedures for recovery from an upset, as in the prior art URT programs,but cannot execute the procedures in the real world because he or shehas not been prepared to cope with the physiological stresses to befaced, then safety is compromised. The URT process of the presentinvention addresses this deficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a prior art “six post” or “hexapod” platform.

FIG. 2 illustrates a “Level D” simulator.

FIG. 3 illustrates a GYROLAB Advanced Spatial Disorientation Trainerinteractive training system.

FIG. 4 illustrates lift vector control.

FIG. 5 illustrates an aircraft V-n diagram.

FIG. 6 illustrates a GYROLAB GL-1500 simulator.

FIG. 7 illustrates a GYROLAB GL-2500 simulator.

FIG. 8 illustrates a GYROLAB GL-4000 simulator.

FIG. 9 illustrates a GYROLAB GL-6000 simulator.

DETAILED DESCRIPTION

Loss of Control continues to be a major factor in fatal aircraftaccidents. Realistic training for this unpredictable and disorientingevent is very difficult for a number of reasons. Prior art flightsimulators cannot reproduce the sustained angular and G accelerationsthat would be present in an actual LOC situation. Upset recoverytraining in transport or normal category aircraft cannot be safelyconducted because it is far too difficult and dangerous, and theseaircraft are not designed to routinely handle the flight conditionsassociated with many upset conditions. Training done in aerobaticaircraft, while helpful, does not duplicate the skill set needed torecover a large aircraft and, in some cases, may actually hinder a largeaircraft pilot's ability to recover since the flight performance andcharacteristics of the aerobatic aircraft do not match those of thetransport/normal category aircraft.

Generally, embodiments of the present invention provide sustainedG-force multi-axis simulator-based upset recovery training for pilotswhile advantageously accurately recreating the dynamics experiencedwhile airborne.

Reference herein to “one embodiment”, “an embodiment”, or similarformulations, means that a particular feature, structure, operation, orcharacteristic described in connection with the embodiment, is includedin at least one embodiment of the present invention. Thus, theappearances of such phrases or formulations herein are not necessarilyall referring to the same embodiment. Furthermore, various particularfeatures, structures, operations, or characteristics may be combined inany suitable manner in one or more embodiments.

The illustrative URT program disclosed herein, using a sustained G-forcemulti-axis platform, trains pilots to deal with the sensory assault thatoccurs during an upset.

Illustrative Embodiment

The GYROLAB Advanced Spatial Disorientation Trainer (ASDT), fromEnvironmental Tectonics Corporation, is a state-of-the-art, interactivetraining system. See FIG. 3.

In the GYROLAB ASDT's simulated aircraft flight environment, traineeslearn to rely on their flight instruments to maintain control.Interactive learning profiles and closed-loop flight controls allow thetrainee to practice control actions.

The GYROLAB ASDT can simulate the in-flight stimulation of the visual,vestibular, and proprioceptive systems that can cause pilots to becomedisoriented while flying. The GYROLAB ASDT has the unique capability toprovide controlled, sustained G-stimulation with its planetary axis, and±360 degree rotation in the yaw, pitch and roll axes. These capabilitiesmake the GYROLAB ASDT a powerful tool for URT, in addition tosituational awareness training.

In the URT program in accordance with the present invention, the goal isto train pilots to return the aircraft to a controlled, stabilizedflight with minimal deviations in altitude, airspeed, and heading whilemaintaining aircraft limits and avoiding impact with the ground andother aircraft. This is done through applying both a set of generalskills and a set of specific techniques for given circumstances.

The URT program in accordance with the present invention provides thetrainee with a general set of guidelines that must be interpreted andapplied to the given upset situation.

With regard to the general set of guidelines, the trainees will beprovided information on aircraft control, upset specifics, and recoveryprocedures and techniques. With respect to aircraft control, informationon the basic premises of aircraft control beyond the normal flightenvelope (i.e., extreme maneuvering) is provided. With respect to upsetspecifics, information regarding what makes an upset and how upsets arecategorized is provided. With respect to recovery, information on a baseset of procedures and techniques that can be applied is provided.

With regard to aircraft control, most commercial aviation flighttraining occurs in the normal flight envelope. However, upsets takeplace outside the normal flight envelope and (in some instances) beyondthe operational limits of the aircraft. Thus, in order to recover froman upset, the pilot must learn to control the aircraft to a levelgreater than that learned in previous training.

The two most important skills in controlling an aircraft are lift vectorcontrol and energy management (EM). EM ensures that the aircraftenergies are appropriately stored and expended. Lift vector controlensures that application of energies results in the correct aircraftmotion. The basic flying skills that many commercially-trained pilotshave been taught are sub-sets of lift vector control and EM focused onspecific flight conditions in the center of the operating envelope.

With regard to lift vector control, lift vector is a term that refers tothe magnitude and direction of the lifting force. The lift vector isgenerally pointed perpendicular to and away from the upper surface ofthe wing. The direction of the lift vector is controlled by bank andpitch. The nose of the airplane moves in the direction of the liftvector minus the effects of gravity.

Most airline pilots have learned some basic concepts of lift vectorcontrol. They have been taught that an airplane turns by using theailerons/spoilers to tilt the lift force in the direction of the turn.They have also been taught that when tilted, a component of the liftingforce is used to the turn the airplane, hence they must increase theangle-of-attack (AoA) to account for the lift needed to turn. This is anexample of lift vector control a depiction of which can be seen in FIG.4.

The magnitude of the lift vector is called the load factor, or what iscommonly called “G force.” Load factor is measured in multiples of theforce of gravity or “G's”. For instance, if the airplane is generatingtwice as much lift as its weight it would then be experiencing a loadfactor of 2 or pulling 2 G's. In straight and level flight the liftvector is pointed up and has a load factor of approximately 1 G.Increasing load factor increases the rate at which the aircraft isexpending energy.

Load factor also influences stall speed. At a given airspeed, loadfactor is increased by increasing AoA. As an airplane stalls at a fixedangle of attack, increasing load factor will bring you closer to orexceed the stall AoA. Exceeding the stall AoA is what is generallyreferred to as an accelerated stall. Conversely, a load factor of lessthan 1 corresponds to a reduction in AoA from straight and level flight.At a load factor of zero the airplane is not generating any lift andhence by definition cannot stall.

Given the relationship of load factor to stall and EM, reducing loadfactor in some upset recovery situations can be a effective method ofavoiding loss of consciousness, increasing controllability, and reducingenergy loss. The phrase “unloading an airplane” refers to the consciousact of decreasing load factor.

The total energy state of the aircraft is a combination of the dynamicenergy of the airframe, consisting of altitude, airspeed and aircraftflight attitude, and the available energy from the engines. Theseenergies must counteract the external forces at work on the airplane,namely gravity and drag. Knowledge of the energy state of the aircraftmust become a constant part of the pilot's situational awareness.

An airplane possesses three kinds of energy. In order to effectivelymaneuver an aircraft, a pilot must learn to balance and apply thoseenergies effectively. The three energy types are Kinetic Energy (KE),Potential Energy (PE) and Chemical Energy (CE). When a vehicle is inmotion it possesses energy due to momentum. This energy is referred toas kinetic energy and increases with the square of true airspeed (TAS)for a given aircraft. Hence, higher airspeed equals higher kineticenergy. Potential energy is the energy an object has due gravity'sability to pull it towards the center of the Earth.

Hence, higher altitude results in higher potential energy. For example,if you push a cart up a hill, it can then roll back down the hill. Bypushing the cart up the hill you have given that cart potential energy.Chemical energy results from the burning of fuel in the engine to createthrust. Chemical energy allows the pilot to add energy to the aircraftand keep it aloft. No fuel equals no chemical energy.

All three energy types are interrelated. For example, if you have highairspeed or high KE you can pull the nose up and gain altitude, or PE,but you will slow down, losing KE. This is called trading airspeed foraltitude. Potential energy can be converted to kinetic energy by diving,which increases airspeed, or trading altitude for airspeed. Chemicalenergy is burning fuel which becomes thrust and is used to increaseeither kinetic energy or potential energy, i.e., used to increaseairspeed or altitude respectively. Effectively controlling theseenergies and the relationships between them is what is meant by theexpression “energy management”.

A properly flying airplane has a balanced mix of all three energy types:KE, PE and CE. This involves keeping KE within limits (Vs [the stallspeed, or minimum steady flight speed for which aircraft is stillcontrollable] to V_(NE) [the never exceed speed], G within limits),while ensuring adequate PE (safe altitude) and sufficient CE (fuelremaining).

Many upsets occur when an airplane is approaching or reaches an unsafeenergy state. Recovering from an upset requires effective EM to restoreand/or maintain the aircraft in a safe flight condition.

Since EM is a balance, applying energies to one parameter can cost inothers. A common mistake made by pilots is to maximize performance ofone parameter at the cost of the others that could be better budgeted toeffect recovery. An example would be a scenario of an aircraft landingshort of a runway. Many short landing incidents have taken place as apilot, nearing the ground short of the runway, continues adding backpressure thereby increasing AoA in an attempt to arrest sink rate. Thepilot in this case is max performing available AoA. Unfortunately, theincreased AoA also increases drag reducing ground speed and increasingsink rate resulting in an even shorter touchdown. What may have been amore suitable response is to lower the nose decreasing drag, increasingairspeed and KE thus carrying the airplane further over the ground.While lowering the nose may be counterintuitive it would increase thelikelihood of making the runway. This example of course is general andeach situation must be judged on its own merits. The fact that no twoincidents are alike is what makes EM a critical skill to learn and adifficult skill to teach.

Until now, pilots have been trained to fly their airplanes in the heartof its operating envelope (i.e., the normal flight envelope). Successfulupset recovery maneuvering may require the pilot to fly the airplane tothe edge of its limitations (i.e., extreme maneuvering). However,exceeding these limitations is dangerous, and in some cases could bemore dangerous, than the initial upset. There are documented cases ofair transport upsets where the airplane was recovered but the upsetrecovery maneuvering resulted in passenger injuries and fatalities.Accordingly, upset training includes training in extreme maneuvering, sothat the pilot can safely and effectively control the aircraft in anupset situation.

In basic pilot training, pilots learn that V_(A) is the maximum speed atwhich full smooth deflection of a single control surface can be appliedwithout damaging the airframe. V_(A) actually provides a more generalmetric of aircraft performance. V_(A) is the airspeed where maximumallowable G and critical AoA coincide. At speeds below V_(A) theaircraft is lift limited. In other words, KE is not sufficient togenerate enough lift, and therefore G, to exceed structural limits.Excessive back pressure will result in a stall before limits areexceeded. At speeds above V_(A), you will reach the maximum allowable Gbefore you reach the critical AoA. In this case, excessive back pressurecan generate G sufficient to exceed structural limits and airframedamage may result before the airplane stalls. Furthermore, the turnradius of an airplane is a function of G and airspeed, the maximum G andthe minimum airspeed, which is again V_(A), will give you the smallestturn radius, or in the case of a dive recovery the minimum altitudeloss. For these reasons, a pilot must know the maneuvering speed of theaircraft so that he can fly the airplane appropriately for conditions.

The relationship of aircraft limitations versus airspeed can be seengraphically in the aircraft V-n diagram an example of which is shown inFIG. 5. Every aircraft has a similar plot which shows the load factorlimits of the aircraft as compared to airspeed. In the curved part ofthe diagram, below V_(A), the airplane will stall at the load factorshown. Above V_(A) the aircraft structural components are in danger offailing.

The definition of upsets and their causes are discussed above and inprior art training URT programs.

However, upsets are not just caused by external factors, but can becaused in the pilot response to an unfamiliar flight condition or to animproper response to an initial upset. The latter are referred to assecondary upsets. Most new pilots are not familiar with the indicationsand physical sensations associated with high G, and attitude maneuveringsuch as aerobatics or upset recovery. As a result, their responses tothe initial upset may not be correct and may lead to a secondary upset.

Many pilots find themselves in real world upsets unprepared for theforces they will experience. The result can startle the pilot. This isfollowed by a cascading of perceptions due to unfamiliar motions andaccelerations, which eventually overwhelm the pilot and lead to thepilot reverting to executing a previously learned skill that isappropriate for a similar, but different flight condition, which resultsin the selection and execution of an inappropriate skill. For example, apilot who misdiagnoses a relatively benign upset, such as a mildlyinverted (greater than 90 degrees of bank, but less than 180 degrees ofbank)/nose low/low energy situation, may drastically exacerbate theproblem by pulling back on the yoke, thereby increasing AoA and pullingthrough a “Split S” type of maneuver, dramatically increasing airspeed,losing altitude and overstressing the aircraft. In this case, the pilotreverted to a behavior that is appropriate for normal flight envelopeflight (i.e., pull back on the yoke to gain altitude) that wascompletely inappropriate for the upset condition and executed thatbehavior because he misinterpreted the initial upset. So, while theinitial event may have been externally induced, a resulting more severeupset may be caused by pilot misperceptions and lack of training toapply proper recovery actions. In addition, there is a dynamicinteraction between a pilot's spatial orientation and upset recoveryperformance—there is a continuum of cause and effect: upset leads todisorientation and disorientation leads to upset.

Proper interpretation and reaction to the initial upset is critical inorder to avoid these secondary upsets. The only real practicalcomparisons to maneuvering an airplane in a real world, high stress, anddynamic upset environments is a multi-axis, sustained motion, sustainedG simulator or a real airplane. Historically most pilots have notreceived training in either. The URT program in accordance with thepresent invention addresses this deficiency.

In the URT program in accordance with the present invention, traineesreceive training on upsets and recovery techniques in a classroomsetting, and then the trainees will be asked to recover from a specificset of upset scenarios that correspond to selected actual accidentsreported on by the National Transportation Safety Board (NTSB).

For the simulator training, the simulator will be set up to emulate ageneric transport aircraft with flight characteristics that are similarto that of a commercial aircraft. Other set ups emulating other types ofaircraft are possible.

During the simulator flights, the pilots are asked to recover fromvarious upset conditions. Each upset scenario is typically automated.The simulator flies the pilot into the upset condition and the pilot isinstructed to recover.

In accordance with the present invention, the simulator used is amulti-axis, sustained motion simulator that is capable of sustainingG-levels that would be encountered during the upset situation.

During the training, pilot performance data may be collected. Collecteddata may include, but is not limited to, flight control inputs, flightpath data, G levels attained, reaction times, and closed circuit TVfootage.

Physiological data may be taken in order to measure levels of stressduring the upset and recovery. All physiological monitoring is typicallynoninvasive and preferably will not cause subject discomfort. Themonitoring equipment may include, but is not limited to, a finger tiptype pulse monitor; a cuff type blood pressure monitor; a temperaturemonitor that will applied via adhesive patch; two electrodes to measureeye movement that may be applied via adhesive patch, one above the eyeand one outboard of the eye; and two elastic straps that may be placedaround the abdomen to measure respiration rate and depth.

An illustrative URT program, in accordance with the present invention,may employ upset categories based on: Unusual Attitudes; Energy state;Structural conditions; and Environmental conditions. Unusual attitudesare summarized as follows:

-   No/Low Bank Angle, defined as 0° to 30° L/R (referenced to horizon).-   High Bank Angle, defined as 31° to 90° L/R (referenced to horizon).-   Inversion (inversion of aircraft referenced to longitudinal axis),    defined as 90° to 270° (referenced to horizon).-   Nose low, defined as −10° to −90° (referenced to horizon).-   Nose high, defined as +20° to +90° (referenced to horizon).

Table I, below, lists upset categories that may also be employed:

TABLE I Pitch Angle Energy State Bank Angle 1 High High No/Low 2 HighHigh High 3 High High Inverted 4 High Low No/Low 5 High Low High 6 HighLow Inverted 7 Low High No/Low 8 Low High High 9 Low High Inverted 10Low Low No/Low 11 Low Low High 12 Low Low Inverted

The following upset categories may also be employed: Out of Control(00C) Flight, such as Stalls, Spins, Overspeeds, Underspeeds, andDepartures from controlled flight; Environmental (e.g., wake turbulenceor severe weather); and Mechanical (e.g., aircraft structural damage ormalfunction).

In an alternative embodiment, the URT Program of the present inventionis provided using a simulator similar to the GL-1500, manufactured byEnvironmental Tectonics Corporation. See FIG. 6.

In a further alternative embodiment, the URT Program in accordance withthe present invention is provided using a simulator similar to theGL-2000, manufactured by Environmental Tectonics Corporation. See FIG.3. The GL-2000 is one of the simulators used to conduct the URT programin accordance with the present invention. It is designed to keep pacewith changing training needs. An Interactive Profile Editor allowsinstructors to change any existing training profiles or create newtraining profiles as their students' training needs dictate. Interactivelearning profiles and closed-loop flight controls allow the trainee topractice control actions. The Interactive Profile Editor features afamiliar and easy to use Windows® based Graphical User Interface.

In a further alternative embodiment, the URT Program in accordance withthe present invention is provided using a simulator similar to theGL-2500, manufactured by Environmental Tectonics Corporation. See FIG.7.

In a further alternative embodiment, the URT program in accordance withthe present invention is provided using a simulator similar to theGL-4000, manufactured by Environmental Tectonics Corporation. See FIG.8. The GL-4000 offers sustained G motion cueing in a high fidelityAuthentic Tactical Flight Simulator. It combines full-fidelity andsustained G motion cueing. A pilot can experience the same missionstress scenarios incurred when flying a real aircraft in the GL-4000.This capability results in maximum learning benefits. The GL-4000 iscontrolled by the pilot's commands in response to perceived flightconditions in the device. It accurately replicates the three componentsof rectilinear acceleration which are produced by a maneuveringaircraft. The advantage of a sustained G dynamic flight simulator overconventional simulators is the capability to produce sustained elevatedG levels and a realistic, yet safe, controlled flight environment.

In a still further alternative embodiment, the URT Program in accordancewith the present invention is provided using a simulator similar to theGL-6000, manufactured by

Environmental Tectonics Corporation. The GL-6000 offers advancedcapabilities in motion technology for research and training in shorttakeoff and landing (STOL), vertical takeoff and vertical landing(VTOL), and short takeoff and vertical landing (STOVL) dynamic flight,flight phase transition training, dynamic G tolerance and spatialorientation; and includes six axes of motion (rotary, pitch, roll, yaw,vertical, heave), 360 degree continuous rotation in four axes (rotation,pitch, roll, yaw), ±3 feet vertical travel, maximum G of ±3 Gx, Gz, andGy, and a wide field of view visual display. The GL-6000 also offerscapabilities in situational awareness, fatigue countermeasures andadaptation to unusual acceleration environments. The GL-6000 alsosupports research in road vehicle, cars and trucks. This advancedtraining and research device is compatible with interchangeable cockpitswith wide field-of-view visual displays and medical and performancemonitoring and data acquisition.

One illustrative method of operating a flight training simulator, inaccordance with the present invention includes providing a sustained G,multi-axis, centrifuge-based flight training simulator having a cockpitunit with ±360 degrees rotation in the yaw, pitch and roll axes;providing the flight simulator with an operational profile of apre-determined aircraft; and operating the sustained G, multi-axis,centrifuge-based flight training simulator to provide an upsetcondition; wherein the operation of the flight training simulatorproduces continuous G forces and/or rotational cues during the simulatedflight, the continuous G forces substantially matching the actual Gforces occurring in an aircraft during the same upset condition.

An illustrative method of upset recovery training, includes providing asustained G, multi-axis, centrifuge-based flight simulator having acockpit unit with ±360 degrees rotation in the yaw, pitch and roll axes;providing the flight simulator with an operational profile of apre-determined aircraft; operating the sustained G, multi-axis,centrifuge-based flight simulator to provide an upset condition; andexposing a trainee to continuous G forces and rotational cues, duringthe operation of the flight simulator, the continuous G forcessubstantially matching the actual G forces occurring in an aircraftduring the same upset condition.

Another illustrative method of upset recovery training, includesproviding a sustained G, multi-axis, centrifuge-based flight simulatorhaving a cockpit unit with ±360 degrees rotation in the yaw, pitch androll axes; providing the flight simulator with an operational profile ofa pre-determined aircraft; operating the sustained G, multi-axis,centrifuge-based flight simulator to provide an upset condition; andexposing a trainee to a set of continuous motions and G forces, duringthe operation of the flight simulator, the set of continuous motions andG forces substantially matching the actual G forces occurring in thepre-determined aircraft during the same upset condition such thatspatial disorientation occurs in the trainee.

Conclusion

The exemplary methods and apparatus illustrated and described hereinfind application in at least the fields of upset recovery training,spatial disorientation training, and flight simulation.

Through the employment of advanced simulation devices and methods inaccordance with the present invention, aviators can be exposed tonormally dangerous flight conditions in a safe and controlledenvironment. Recreation of aircraft upsets caused by any number ofreasons, such as human error, mechanical malfunctions, environmentalconditions, and so on, allows aviators to explore the extremes of theflying envelope in order to develop the needed skills and techniques toprevent a disaster. URT methods and apparatus in accordance with thepresent invention allow trainees to gain confidence as they experience amultitude of scenarios that include aspects such as spatialdisorientation, wake turbulence, and mechanically induced errors.Trainees experience the effects of relevant human factors (e.g.,physiological, psychological) that are difficult if not dangerous torecreate while airborne.

One advantage of the present invention is an increase in an aviator'ssituational awareness and airmanship so that if an upset condition isencountered, then the aviator can safely recover the aircraft to normalflight parameters.

It will be understood that various other changes in the details,materials, and arrangements of the parts and steps which have beendescribed and illustrated in order to explain the nature of thisinvention may be made by those skilled in the art without departing fromthe principles and scope of the invention as expressed in the subjoinedClaims and their equivalents.

What is claimed is:
 1. A method of upset recovery training, comprising:providing a sustained G, multi-axis, centrifuge-based flight simulatorhaving a cockpit unit with ±360 degrees rotation in the yaw, pitch androll axes; providing the flight simulator with an operational profile ofa pre-determined aircraft; operating the sustained G, multi-axis,centrifuge-based flight simulator to provide a first-upset conditioncorresponding to a simulated-environmentally induced event including atleast one of the following events: turbulence; clear air turbulence,mountain wave turbulence, wind shear, thunderstorms, microbursts, waketurbulence, and airplane icing; exposing a trainee to a first set ofcontinuous motions and G forces, during the operation of the flightsimulator, the first set of continuous motions and G forcessubstantially matching the actual G forces occurring in thepre-determined aircraft during the first upset condition such thatspatial disorientation occurs in the trainee; receiving, at the flightsimulator, flight control inputs from the trainee in response to thefirst-upset condition; operating the sustained G, multi-axis,centrifuge-based flight simulator to provide a second-upset condition inresponse to incorrect-flight control inputs received from the trainee inresponse to the first-upset condition, wherein the second-upsetcondition is inadvertently induced by the trainee; and exposing thetrainee to a second set of continuous motions and G forces, during theoperation of the flight simulator, wherein the second set of continuousmotions and G forces are different than first set of continuous motionsand G forces, and wherein the second set of continuous motions and Gforces substantially match the actual G forces occurring in thepre-determined aircraft during the second-upset condition, such thatspatial disorientation occurs in the trainee.
 2. The method of claim 1,wherein the first or second upset condition includes a selected one ofthe group of conditions consisting of pitch attitude greater than 25degrees nose up; pitch attitude greater than 10 degrees nose down; bankangle greater than 45 degrees; and flying at airspeeds inappropriate forthe conditions.
 3. The method of claim 1, wherein the first or secondupset condition comprises an unusual attitude, wherein the unusualattitude is selected from the group of conditions consisting of a No/LowBank Angle, consisting of an angle between 0° and 30° L/R referenced tothe horizon; a High Bank Angle, consisting of an angle between 31° and90° L/R referenced to the horizon; Inversion, consisting of an anglebetween 90° and 270° referenced to the horizon and rotation about alongitudinal axis; and Nose low consisting of an angle between −10° to−90° referenced to the horizon; and Nose high, consisting of an angle+20° to +90° referenced to the horizon.
 4. The method of claim 3,wherein the first or second upset condition includes a Nose High pitchangle and a No/Low Bank Angle.
 5. The method of claim 3, wherein thefirst or second upset condition includes a Nose High pitch angle and aHigh Bank Angle.
 6. The method of claim 3, wherein the first or secondcondition includes a Nose High pitch angle and an Inverted Bank angle.7. The method of claim 3, wherein the first or second-upset conditionincludes a Nose High pitch angle and an No/Low Bank angle.
 8. The methodof claim 3, wherein a the first or second upset condition includes aNose High pitch angle and a High Bank angle.
 9. The method of claim 3,wherein the first or second upset condition includes a Nose High pitchangle and an Inverted Bank angle.
 10. The method of claim 3, wherein thefirst or second upset condition includes a Nose Low pitch angle and aNo/Low Bank angle.
 11. The method of claim 3, wherein the first orsecond upset condition includes a Nose Low pitch angle-and a No/Low Bankangle.
 12. The method of claim 3, wherein the first or second upsetcondition includes a Nose Low pitch angle and an Inverted Bank angle.13. The method of claim 3, wherein the first or second upset conditionincludes a Nose Low pitch angle and a No/Low Bank angle.
 14. The methodof claim 3, wherein the first or second upset condition includes a NoseLow pitch angle and a High Bank angle.
 15. The method of claim 3,wherein the first or second upset condition includes a Nose Low pitchangle and an Inverted Bank angle.
 16. The method of claim 1, furthercomprising collecting pilot performance data.
 17. The method of claim16, wherein pilot performance data includes one or more of the groupconsisting of flight control inputs, flight path data, G levelsattained, reaction times, and closed circuit N footage.
 18. A method ofupset recovery training, comprising: providing a sustained G,multi-axis, centrifuge-based flight simulator having a cockpit unit with±360 degrees rotation in the yaw, pitch and roll axes; providing theflight simulator with an operational profile of a pre-determinedaircraft; operating the sustained G, multi-axis, centrifuge-based flightsimulator to provide a first-upset condition corresponding to asimulated-environmentally induced event; and exposing a trainee tocontinuous rotational cues, during the operation of the flightsimulator, the continuous rotational cues substantially matching theactual rotational cues occurring in the pre-determined aircraft duringthe first-upset condition; and receiving, at the flight simulator,flight control inputs from the trainee in response to the first-upsetcondition; operating the sustained G, multi-axis, centrifuge-basedflight simulator to provide a second-upset condition based on the flightcontrol inputs received from the trainee in response to the first-upsetcondition, wherein the second-upset condition is inadvertently inducedby the trainee as a result of attempting to recover from the first-upsetcondition; and exposing the trainee to a set of continuous motions and Gforces, during the operation of the flight simulator, wherein set ofcontinuous motions and G forces substantially match the actual G forcesoccurring in the pre-determined aircraft during the second-upsetcondition, such that spatial disorientation occurs in the trainee. 19.The method of claim 18, wherein the first or second upset condition isoutside the normal operational envelope of the pre-determined aircraft.20. The method of claim 18, wherein the second upset condition is astall.
 21. The method of claim 18, wherein the first or second upsetcondition is a spin.
 22. The method of claim 18, wherein the secondupset condition is an overspeed condition.
 23. The method of claim 18,wherein the second upset condition is an underspeed condition.
 24. Themethod of claim 18, wherein the first upset condition is waketurbulence.
 25. The method of claim 18, wherein the first upsetcondition is aircraft structural damage.
 26. The method of claim 18,wherein the first upset condition is an aircraft malfunction.